WO2023246134A1 - Feuille d'électrode, ensemble d'électrodes, élément de batterie, batterie et dispositif électrique - Google Patents

Feuille d'électrode, ensemble d'électrodes, élément de batterie, batterie et dispositif électrique Download PDF

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Publication number
WO2023246134A1
WO2023246134A1 PCT/CN2023/077463 CN2023077463W WO2023246134A1 WO 2023246134 A1 WO2023246134 A1 WO 2023246134A1 CN 2023077463 W CN2023077463 W CN 2023077463W WO 2023246134 A1 WO2023246134 A1 WO 2023246134A1
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WO
WIPO (PCT)
Prior art keywords
edge
current collector
electrode
along
active material
Prior art date
Application number
PCT/CN2023/077463
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English (en)
Chinese (zh)
Inventor
黄玉平
喻鸿钢
马云建
Original Assignee
宁德时代新能源科技股份有限公司
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Publication of WO2023246134A1 publication Critical patent/WO2023246134A1/fr

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/20—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders
    • H01M50/244—Secondary casings; Racks; Suspension devices; Carrying devices; Holders characterised by their mounting method
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/20—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders
    • H01M50/249—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders specially adapted for aircraft or vehicles, e.g. cars or trains
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/531—Electrode connections inside a battery casing
    • H01M50/533—Electrode connections inside a battery casing characterised by the shape of the leads or tabs
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present application relates to the field of battery technology, specifically, to a pole piece, an electrode assembly, a battery cell, a battery and electrical equipment.
  • Electric vehicles have become an important part of the sustainable development of the automobile industry due to their advantages in energy conservation and environmental protection.
  • battery technology is an important factor related to their development.
  • the purpose of this application is to provide a pole piece, electrode assembly, battery cell, battery and electrical equipment.
  • the battery cell composed of the pole piece has high safety.
  • the present application provides a pole piece, including: a current collector; an active material layer coated on the surface of the current collector; wherein the active material layer includes opposite electrodes along the width direction of the current collector. A first edge and a second edge, the first edge extending undulatingly along the length direction of the current collector.
  • the first edge is an edge of the active material layer in the width direction of the current collector, and the first edge extends undulatingly along the length direction of the current collector, so that one edge of the current collector in the width direction
  • the coating area of the active material layer on one edge in the width direction of the current collector is smaller, thereby reducing the probability of lithium precipitation during the use of the battery cell composed of the pole piece. Improved battery cell safety.
  • the first edge is wavy.
  • the shape of the first edge is wavy, which facilitates coating of the active material layer on the surface of the current collector and is simple to operate.
  • the second edge extends undulatingly along a length direction of the current collector.
  • the second edge extends undulatingly along the length direction of the current collector, so that the other edge of the current collector in the width direction has an empty foil area that is not coated with the active material layer, further reducing the battery cell composed of the pole piece.
  • the probability of lithium precipitation during use improves the safety of battery cells.
  • the second edge is wavy.
  • the shape of the second edge is wavy, which facilitates coating of the active material layer on the surface of the current collector and is simple to operate.
  • the first edge is symmetrical to the second edge.
  • the first edge and the second edge are symmetrical, which facilitates coating of the active material layer.
  • the current collector includes a body and a plurality of tabs, the body includes third edges and fourth edges oppositely arranged along the width direction of the current collector, and the tabs are formed from the A third edge extends out, the active material layer is coated on the surface of the body, the first edge is close to the third edge, and the second edge is close to the fourth edge.
  • the tab extends from the third edge, and the first edge is closer to the third edge than the second edge, so that the area of the active material layer coated on the area of the body close to the tab is smaller, reducing the composition of the pole piece. The probability of lithium precipitation occurring in a battery cell during use.
  • the third edge extends straight along the length direction of the current collector, and the maximum distance between the first edge and the third edge along the width direction of the current collector is D, the width of the current collector is W, satisfying 1/10 ⁇ D/W ⁇ 1/6.
  • the ratio between the maximum distance D between the first edge and the third edge and the width W of the current collector satisfies the above relationship, which can balance the energy density of the battery cell and the probability of lithium deposition.
  • the ratio of the maximum distance D between the first edge and the third edge to the width W of the current collector is less than 1/10, the probability of lithium deposition on the pole piece of the battery cell is greater; when the first edge and the third edge
  • the ratio between the maximum distance D and the width W of the current collector is greater than 1/6, the area of the active material layer coated by the current collector is smaller, resulting in a lower energy density of the battery cell.
  • the fourth edge extends undulatingly along the length direction of the current collector and at least partially coincides with the second edge.
  • the fourth edge relative to the fourth edge extending linearly along the length direction of the current collector, the fourth edge extends undulatingly along the length direction of the current collector and the fourth edge and the second edge at least partially overlap, so that the active material layer is on the body.
  • the coating area on the side away from the third edge is smaller, which reduces the coating area of the active material layer on the edge in the width direction of the current collector, thereby reducing the risk of lithium precipitation in the battery cell composed of the pole piece.
  • the fourth edge extends straight along a length direction of the current collector.
  • the fourth edge extends along a straight line to facilitate coating of the active material layer.
  • the first edge includes a plurality of protruding segments protruding toward the third edge, and the plurality of protruding segments are spaced apart along the length direction of the current collector, and the plurality of protruding segments are arranged at intervals along the length direction of the current collector.
  • the pole tabs are spaced apart along the length direction of the current collector, and each pole tab is located between two adjacent protruding sections.
  • the pole tabs correspond to two adjacent protruding segments to reduce the probability of lithium precipitation in the body at the position corresponding to the pole tabs.
  • the center line of each pole lug deviates from the symmetrical center line of the two protruding segments adjacent to the pole lug.
  • the present application provides an electrode assembly, including a positive electrode piece, a separator, and a negative electrode piece.
  • the positive electrode piece, the separator, and the negative electrode piece are stacked and rolled to form the electrode assembly, and the The positive electrode piece and the negative electrode piece are the electrode pieces described in the above embodiments.
  • the positive electrode piece and the negative electrode piece are the above-mentioned electrode pieces, which can reduce the risk of lithium precipitation in the battery cell composed of the electrode assembly and improve the safety of the battery cell.
  • the present application provides a battery cell, including the electrode assembly as described in the above embodiment.
  • the battery cell according to the embodiment of the present application adopts the above-mentioned electrode assembly and has high safety.
  • the battery cell further includes: a housing having an opening; an end cover closing the opening; a first electrode terminal and a second electrode terminal disposed on the end cover; a first set The current member and the second current collecting member; wherein, the electrode assembly is accommodated in the housing, the extension direction of the winding axis of the electrode assembly is perpendicular to the thickness direction of the end cap, and the positive electrode of the electrode assembly
  • the ears and the negative electrode tabs are respectively located on both sides of the electrode assembly in the extension direction of the winding axis.
  • the positive electrode tabs are electrically connected to the first electrode terminal through the first current collecting member, and the The negative electrode tab is electrically connected to the second electrode terminal through the second current collecting member.
  • the present application provides a battery, including the battery cell as described in the above embodiment.
  • the present application provides an electrical device, including the battery as described in the above embodiment.
  • Figure 1 is a schematic structural diagram of a vehicle provided by some embodiments of the present application.
  • Figure 2 is an exploded view of a battery provided by some embodiments of the present application.
  • Figure 3 is a cross-sectional view of a battery cell provided by some embodiments of the present application.
  • Figure 4 is a schematic structural diagram of a pole piece provided by some embodiments of the present application.
  • Figure 5 is a left view of Figure 4.
  • Figure 6 is a schematic structural diagram of the first edge of the pole piece provided by some embodiments of the present application.
  • Figure 7 is a schematic structural diagram of a pole piece provided by other embodiments of the present application.
  • Figure 8 is a left view of Figure 7;
  • Marking description 100-battery; 10-box; 11-first part; 12-second part; 20-battery cell; 21-casing; 22-end cover; 23-electrode assembly; 241-first electrode terminal ; 242-second electrode terminal; 251-first current collecting member; 252-second current collecting member; 30-pole piece; 31-current collector; 311-body; 3111-third edge; 3112-fourth edge; 312-pole tab; 312a-positive pole tab; 312b-negative pole tab; 32-active material layer; 321-first edge; 3211-first straight section; 3212-first curve section; 3213-protruding section; 322-the second edge; 3221-the second straight section; 3222-the second curve section; 200-controller; 300-motor; 1000-vehicle.
  • an embodiment means that a particular feature, structure or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application.
  • the appearances of this phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those skilled in the art understand, both explicitly and implicitly, that the embodiments described herein may be combined with other embodiments.
  • multiple refers to more than two (including two).
  • multiple groups refers to two or more groups (including two groups), and “multiple pieces” refers to means two or more pieces (including two pieces), unless otherwise clearly and specifically limited.
  • the battery mentioned in the embodiments of this application refers to a single physical module including one or more battery cells to provide higher voltage and capacity.
  • Batteries generally include a box for packaging one or more battery cells. The box can prevent liquid or other foreign matter from affecting the charging or discharging of the battery cells.
  • the battery cell includes an electrode assembly and an electrolyte.
  • the electrode assembly consists of a positive electrode plate, a negative electrode plate and a separator. Battery cells mainly rely on the movement of metal ions between the positive and negative electrodes to work.
  • the positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer.
  • the positive electrode active material layer is coated on the surface of the positive electrode current collector.
  • the positive electrode current collector that is not coated with the positive electrode active material layer protrudes from the positive electrode collector that is coated with the positive electrode active material layer. Fluid, the cathode current collector that is not coated with the cathode active material layer serves as the cathode tab.
  • the material of the positive electrode current collector can be aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganate, etc.
  • the negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer.
  • the negative electrode active material layer is coated on the surface of the negative electrode current collector.
  • the negative electrode current collector that is not coated with the negative electrode active material layer protrudes from the negative electrode collector that is coated with the negative electrode active material layer.
  • Fluid, the negative electrode current collector that is not coated with the negative electrode active material layer serves as the negative electrode tab.
  • the material of the negative electrode current collector can be copper, and the negative electrode active material can be carbon or silicon.
  • the number of positive electrode tabs is multiple and stacked together, and the number of negative electrode tabs is multiple and stacked together.
  • the material of the separator can be PP (polypropylene, polypropylene) or PE (polyethylene, polyethylene), etc.
  • the negative electrode plate, positive electrode plate and separator in the electrode assembly of the lithium-ion battery cell can be rolled or folded and then compacted.
  • lithium ions are deintercalated from the positive electrode piece and embedded in the negative electrode piece.
  • some abnormal situations may occur, such as insufficient space for lithium insertion in the negative electrode piece, and the gap between the negative electrode piece and the positive electrode piece.
  • the distance is too large, the resistance of lithium ions to be inserted into the negative electrode piece is too great, or the lithium ions are deintercalated from the positive electrode piece too quickly.
  • the deintercalated lithium ions cannot be embedded in the negative active material layer of the negative electrode piece in equal amounts, and cannot be embedded in the negative electrode.
  • the lithium ions in the negative electrode can only gain electrons on the surface of the negative electrode, thus forming silvery white metallic lithium element. This is the phenomenon of lithium precipitation.
  • Lithium precipitation not only reduces the performance of lithium-ion battery cells and greatly shortens their cycle life, but also limits the fast charging capacity of lithium-ion battery cells.
  • the precipitated lithium metal is very active and can react with the electrolyte at a lower temperature, causing the battery cell to lower the starting temperature of self-heat generation and self-heat generation. The rate increases, seriously endangering the safety of battery cells.
  • the deintercalated lithium ions can form lithium crystals on the surface of the negative electrode piece, and the lithium crystals can easily pierce the separator, causing the risk of short circuit between adjacent positive electrode pieces and negative electrode pieces.
  • the inventors designed a pole piece after in-depth research.
  • the edge of the active material layer in the width direction of the current collector does not extend to the edge of the current collector, so that An empty foil area is formed near the edge of the current collector.
  • the risk of lithium precipitation in the electrode assembly composed of the pole piece can be reduced, making the battery cell highly safe.
  • the active material layer is coated to the edge of the current collector, and the edge of the active material layer is straight.
  • Linearly extended pole piece In the pole piece of the present application, the edge of the active material layer in the width direction of the current collector is not coated to the edge of the current collector, and the edge of the active material layer extends in an undulating shape, along the edge of the current collector. In the length direction, the distance between the edge of the active material layer and the edge of the current collector is unequal. The position of the current collector close to the edge forms an undulating empty foil area.
  • the battery cells disclosed in the embodiments of the present application can be used in, but are not limited to, vehicles, ships, aircraft, and other electrical equipment.
  • the power supply system of the electrical equipment can be composed of battery cells, batteries, etc. disclosed in this application.
  • Embodiments of the present application provide an electrical device that uses a battery as a power source.
  • the electrical device can be, but is not limited to, vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, electric tools, etc.
  • Vehicles can be fuel vehicles, gas vehicles or new energy vehicles, and new energy vehicles can be pure electric vehicles, hybrid vehicles or extended-range vehicles, etc.
  • spacecraft include aircraft, rockets, space shuttles, spaceships, etc.
  • electric toys include fixed Type or mobile electric toys, such as game consoles, electric car toys, electric ship toys and electric airplane toys, etc.
  • electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools and railway electric tools, for example, Electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, planers and more.
  • the embodiments of this application impose no special restrictions on the above electrical equipment.
  • the following embodiments take the electrical equipment as a vehicle as an example.
  • FIG. 1 is a schematic structural diagram of a vehicle provided by some embodiments of the present application.
  • the battery 100 is disposed inside the vehicle 1000 , and the battery 100 may be disposed at the bottom, head, or tail of the vehicle 1000 .
  • the battery 100 may be used to power the vehicle 1000 , for example, the battery 100 may serve as an operating power source for the vehicle 1000 .
  • the vehicle 1000 may also include a controller 200 and a motor 300 .
  • the controller 200 is used to control the battery 100 to provide power to the motor 300 , for example, for starting, navigating and driving the vehicle 1000 .
  • the battery 100 can not only be used as an operating power source for the vehicle 1000 , but can also be used as a driving power source for the vehicle 1000 , replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000 .
  • the battery 100 includes a case 10 and a plurality of battery cells 20 .
  • the plurality of battery cells 20 are disposed in the case 10 .
  • the box 10 is a component that accommodates the battery cells 20.
  • the box 10 provides a storage space for the battery cells 20.
  • the box 10 can adopt a variety of structures.
  • the box 10 may include a first part 11 and a second part 12 , and the first part 11 and the second part 12 cover each other to define an accommodation space for accommodating the battery cells 20 .
  • the first part 11 and the second part 12 may be in various shapes, such as cuboid, cylinder, etc.
  • the first part 11 may be a hollow structure open on one side, and the second part 12 may also be a hollow structure open on one side.
  • the open side of the second part 12 is covered with the open side of the first part 11 to form a box with accommodating space.
  • the first part 11 may be a hollow structure with one side open
  • the second part 12 may be a plate-like structure
  • the second part 12 covers the open side of the first part 11 to form a box 10 with an accommodation space.
  • the first part 11 and the second part 12 can be sealed by sealing elements, which can be sealing rings, sealants, etc.
  • multiple battery cells 20 can be connected in series, in parallel, or in mixed connection.
  • Mixed connection means that the multiple battery cells 20 are connected in series and in parallel. It can be that multiple battery cells 20 are connected in series or in parallel or mixed to form a battery.
  • Battery module multiple battery modules are connected in series, parallel or mixed to form a whole, and are accommodated in the box 10 . It is also possible that all the battery cells 20 are directly connected in series or in parallel or mixed together, and then the entire battery cell 20 is accommodated in the box 10 .
  • the battery 100 may further include a bus component, through which the multiple battery cells 20 may be electrically connected to achieve series, parallel, or mixed connection of the multiple battery cells 20 .
  • the bus component may be a metal conductor, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.
  • FIG. 3 is a cross-sectional view of a battery cell provided by some embodiments of the present application.
  • the battery cell 20 may include a case 21, an end cap 22, an electrode assembly 23, and an electrode terminal.
  • the housing 21 has an opening, and the end cover 22 and the housing 21 jointly define a sealed space.
  • the housing 21 may be a hollow structure with an opening formed at one end, or the housing 21 may be a hollow structure with openings formed at two opposite ends.
  • the housing 21 can be made of various materials, such as copper, iron, aluminum, steel, aluminum alloy, etc.
  • the end cap 22 is a component that closes the opening of the case 21 to isolate the internal environment of the battery cell 20 from the external environment.
  • the end cap 22 and the housing 21 jointly define a sealed space for accommodating the electrode assembly 23, electrolyte and other components.
  • the end cap 22 can be connected to the housing 21 by welding or crimping to close the opening of the housing 21 .
  • the shape of the end cap 22 can be adapted to the shape of the casing 21.
  • the casing 21 has a rectangular parallelepiped structure, and the end cap 22 has a rectangular plate structure matching the casing 21.
  • the casing 21 is a cylinder. body, and the end cover 22 is a circular plate-shaped structure that matches the housing 21.
  • the end cap 22 can also be made of a variety of materials, such as copper, iron, aluminum, steel, aluminum alloy, etc.
  • the end cap 22 may be provided with electrode terminals, and the electrode terminals may include positive electrode terminals and negative electrode terminals.
  • the electrode assembly 23 is a component in the battery cell 20 where electrochemical reactions occur.
  • the electrode assembly 23 may include a positive electrode piece, a negative electrode piece, and a separator.
  • the electrode assembly 23 may be a rolled structure formed by rolling a positive electrode piece, a separator, and a negative electrode piece.
  • the electrode assembly 23 has a positive electrode tab 312a and a negative electrode tab 312b.
  • the positive electrode tab 312a may be a portion of the positive electrode sheet that is not coated with a positive electrode active material layer
  • the negative electrode tab 312b may be a portion of the negative electrode sheet that is not coated with a negative electrode active material layer.
  • the positive electrode tab 312 a and the negative electrode tab 312 b may extend from both sides in the extension direction N of the winding axis of the electrode assembly 23 .
  • the electrode terminals are arranged on the end cover 22.
  • the number of electrode terminals is two.
  • the two electrode terminals are the first electrode terminal 241 and the second electrode terminal 242 respectively.
  • the positive electrode tab 312a is electrically connected to the first current collecting member 251 through the first current collecting member 251.
  • the electrode terminal 241 and the negative electrode tab 312b are electrically connected to the second electrode terminal 242 through the second current collection member 252 to form a current loop.
  • FIG. 4 is a schematic structural diagram of a pole piece provided by some embodiments of the present application
  • FIG. 5 is a left view of FIG. 4
  • the present application provides a pole piece 30 , which includes a current collector 31 and an active material layer 32 .
  • the active material layer 32 is coated on the surface of the current collector 31 .
  • the active material layer 32 includes a first edge 321 and a second edge 322 opposite along the width direction X of the current collector 31 .
  • the first edge 321 extends undulatingly along the length direction Y of the current collector 31 .
  • the direction indicated by the letter X is the width direction of the current collector 31
  • the direction indicated by the letter Y is the length direction of the current collector 31 .
  • the current collector 31 is a structure or component that collects current.
  • the current collector 31 is usually a metal foil, such as copper foil, aluminum foil, etc.
  • the active material layer 32 is a structure composed of active material materials, and the active material layer 32 may include active material materials, conductive agents, and adhesives.
  • the positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganate.
  • the negative active material can be carbon or silicon.
  • the active material layer 32 may be coated on one side of the current collector 31 in the thickness direction, or the active material layer 32 may be coated on two opposite surfaces of the current collector 31 in the thickness direction Z.
  • the direction indicated by the letter Z is the thickness direction of the current collector 31 .
  • the first edge 321 and the second edge 322 are two opposite edges of the active material layer 32 in the width direction X of the current collector 31 .
  • the first edge 321 and the second edge 322 define the width of the active material layer 32 in the current collector 31 Coating profile in direction X.
  • the first edge 321 Compared with the case where the first edge 321 has a linear structure and the first edge 321 is arranged parallel to the edge in the width direction X of the current collector 31 , the first edge 321 extends undulatingly along the length direction Y of the current collector 31 .
  • the distance between 321 and the edge in the width direction X of the current collector 31 changes along the length direction Y of the current collector 31 , that is, the first edge 321 is uneven.
  • the active material layer 32 is coated on the edge of the current collector 31 in the width direction X, and the edge of the active material layer 32 extends linearly, in the pole piece 30 of the present application, the active material layer 32
  • the first edge 321 in the width direction X of the current collector 31 is not coated to the edge in the width direction Y, a undulating empty foil area is formed near the edge of the current collector 31 (the area of the current collector 31 that is not coated with the active material layer 32).
  • the coating area of the active material layer 32 on the edge of the pole piece 30 is smaller, and the risk of lithium precipitation on the edge of the pole piece 30 is reduced, thereby reducing the risk of lithium precipitation on the electrode assembly 23 and improving the battery cell efficiency. 20 for security.
  • the first edge 321 is wavy.
  • first edge 321 is wavy means that the first edge 321 may be a curved surface.
  • the projection of the first edge 321 on the current collector 31 is in a wavy form.
  • the shape of the first edge 321 is wavy, which facilitates coating of the active material layer 32 on the surface of the current collector 31 and is simple to operate.
  • FIG. 6 is a schematic structural diagram of the first edge of the pole piece provided by some embodiments of the present application.
  • the projection of the first edge 321 on the current collector 31 may include a first straight segment 3211 and a first curved segment 3212.
  • a straight section 3211 extends linearly along the length direction Y of the current collector 31 , and a first curved section 3212 protrudes from the first straight section 3211 along the width direction X of the current collector 31 . That is, the first curved section 3212 is formed by the first The straight section 3211 protrudes toward the edge of the current collector 31 .
  • the edge of the current collector 31 mentioned here refers to the edge close to the first edge 321 in the width direction X of the current collector 31 .
  • the distance between the first straight section 3211 and the edge of the current collector 31 can be the same along the length direction Y of the current collector 31 , or the distance between the first straight section 3211 and the edge of the current collector 31 can be along the length direction Y of the current collector 31 .
  • the length direction Y gradually decreases or gradually increases.
  • the shape of the first curve segment 3212 may be a triangle, a rectangle, a semicircle, a trapezoid, a special shape, etc.
  • the second edge 322 extends undulatingly along the length direction Y of the current collector 31 stretch.
  • the second edge 322 extends undulatingly along the length direction Y of the current collector 31 , and the distance between the second edge 322 and the edge in the width direction X of the current collector 31 changes along the length direction Y of the current collector 31 , that is, the The two edges 322 are uneven.
  • edge in the width direction X of the current collector 31 here refers to the edge in the width direction One edge is closer to the second edge 322.
  • the second edge 322 extends undulatingly along the length direction Y of the current collector 31 , so that the two edges of the current collector 31 in the width direction can have
  • the empty foil area that is not coated with the active material layer 32 further reduces the probability of lithium precipitation in the battery cell 20 composed of the pole piece 30 during use, and improves the safety of the battery cell 20 .
  • the second edge 322 is wavy.
  • the second edge 322 being wavy means that the second edge 322 may be a curved surface.
  • the projection of the second edge 322 on the current collector 31 is in a wavy form.
  • the shape of the second edge 322 is wavy, which facilitates coating of the active material layer 32 on the surface of the current collector 31 and is simple to operate.
  • the projection of the second edge 322 on the current collector 31 may include a second straight section 3221 and a second straight section 3221 .
  • Two curved sections 3222, the second straight section 3221 extends linearly along the length direction Y of the current collector 31, and the second curved section 3222 protrudes from the second straight section 3221 along the width direction X of the current collector 31, that is, the second The curved section 3222 protrudes from the second straight section 3221 toward the edge of the current collector 31 .
  • the edge of the current collector 31 mentioned here refers to the edge close to the second edge 322 in the width direction X of the current collector 31 .
  • the distance between the second straight section 3221 and the edge of the current collector 31 can be the same along the length direction Y of the current collector 31 , or the distance between the second straight section 3221 and the edge of the current collector 31 can be along the length direction Y of the current collector 31 .
  • the length direction Y gradually decreases or gradually increases.
  • the shape of the second curve segment 3222 may be a triangle, a rectangle, a semicircle, a trapezoid, a special shape, etc.
  • the first edge 321 is symmetrical to the second edge 322 .
  • the first edge 321 and the second edge 322 are symmetrical, which facilitates coating of the active material layer 32 .
  • the current collector 31 includes a body 311 and a plurality of tabs 312 .
  • the body 311 includes a third edge 3111 and a third edge 3111 that are oppositely arranged along the width direction X of the current collector 31 .
  • Four edges 3112, the tabs 312 extend from the third edge 3111, the active material layer 32 is coated on the surface of the body 311, the first edge 321 is close to the third edge 3111, and the second edge 322 is close to the fourth edge 3112.
  • the body 311 is a portion of the current collector 31 used for coating the active material layer 32 .
  • the third edge 3111 and the fourth edge 3112 are two edges of the body 311 that are oppositely arranged along the width direction X of the current collector 31 .
  • the third edge 3111 and the fourth edge 3112 define the body 311 in the width direction contour.
  • a plurality of tabs 312 are arranged at intervals along the length direction Y of the current collector 31 .
  • the tabs 312 can be formed by the current collector 31 . 31 is cut, and the third edge 3111 is the cutting edge.
  • the pole tab 312 extends from the third edge 3111 means that the pole tab 312 protrudes from the third edge 3111 in a direction away from the fourth edge 3112 along the width direction X of the current collector 31 .
  • the first edge 321 is close to the third edge 3111 means that the first edge 321 is close to the third edge 3111 relative to the second edge 322. In other words, along the width direction X of the current collector 31, the first edge 321 to the third edge 3111 The distance is greater than the distance from the second edge 322 to the third edge 3111.
  • the second edge 322 being close to the fourth edge 3112 means that the second edge 322 is close to the fourth edge 3112 relative to the first edge 321 .
  • the second edge 322 to the fourth edge 3112 The distance is greater than the distance from the first edge 321 to the fourth edge 3112.
  • the tab 312 extends from the third edge 3111.
  • the first edge 321 is adjacent to the third edge 3111.
  • the first edge 321 and the third edge 3111 define a first empty foil area, so that the area of the body 311 is close to the tab 312.
  • the area of the coated active material layer 32 is smaller, which reduces the probability of lithium precipitation in the edge area of the pole piece 30 close to the tab 312 .
  • the third edge 3111 extends linearly along the length direction Y of the current collector 31 , and along the width direction X of the current collector 31 , the distance between the first edge 321 and the third edge 3111 is The maximum distance is D, the width of the current collector 31 is W, and satisfies 1/10 ⁇ D/W ⁇ 1/6.
  • the third edge 3111 extends linearly along the length direction Y of the current collector 31 , that is, the edge of the body 311 is flush, which facilitates assembly between the pole piece 30 and other components.
  • the ratio between the maximum distance D between the first edge 321 and the third edge 3111 and the width W of the current collector 31 satisfies the above relationship, which can balance the energy density of the battery cell 20 and the probability of lithium deposition.
  • the ratio of the maximum distance D between the first edge 321 and the third edge 3111 to the width W of the current collector 31 is less than 1/10, the probability of lithium deposition in the pole piece 30 of the battery cell 20 is relatively high; when the first When the ratio of the maximum distance D between the edge 321 and the third edge 3111 to the width W of the current collector 31 is greater than 1/6, the area of the active material layer 32 coated by the current collector 31 is smaller, resulting in the energy loss of the battery cell 20 Density is lower.
  • Figure 7 is a schematic structural diagram of a pole piece provided by other embodiments of the present application
  • Figure 8 is a left view of Figure 7.
  • the fourth edge 3112 extends undulatingly along the length direction Y of the current collector 31 and at least partially coincides with the second edge 322 .
  • the fourth edge 3112 and the second edge 322 at least partially overlap means that the fourth edge 3112 and a part of the second edge 322 overlap, or the fourth edge 3112 and the second edge 322 completely overlap.
  • the fourth edge 3112 completely coincides with the second edge 322, which facilitates processing and manufacturing.
  • the fourth edge 3112 extends undulatingly along the length direction Y of the current collector 31 and the fourth edge 3112 and the second edge 322 at least partially overlap, so that the active material layer
  • the coating area of 32 on the side of the body 311 away from the third edge 3111 is smaller, which reduces the coating area of the active material layer 32 on the edge of the current collector 31 in the width direction X, thereby reducing the The risk of lithium precipitation from battery cells 20.
  • the fourth edge 3112 and the second edge 322 at least partially overlap, and the width of the current collector 31 is
  • the upward edge without the pole lug 312 can be die-cut to facilitate the forming and processing of the pole piece 30 .
  • the fourth edge 3112 extends straight along the length direction Y of the current collector 31 .
  • the fourth edge 3112 extends straight along the length direction Y of the current collector 31 , that is, the edge of the body 311 is flush, which facilitates assembly between the pole piece 30 and other components.
  • the fourth edge 3112 extends along a straight line to facilitate coating of the active material layer 32 .
  • the first edge 321 includes a plurality of protruding segments 3213 protruding toward the third edge 3111 , and the plurality of protruding segments 3213 are spaced apart along the length direction Y of the current collector 31 , a plurality of pole tabs 312 are arranged at intervals along the length direction Y of the current collector 31 , and each pole tab 312 is located between two adjacent protruding sections 3213 .
  • the protruding section 3213 refers to the portion of the first edge 321 that is closer to the third edge 3111 relative to other portions.
  • the plurality of protruding sections 3213 are spaced apart along the length direction Y of the current collector 31 , so that the first edge 321 extends in an undulating manner along the length direction Y of the current collector 31 .
  • a recessed section is formed between two adjacent protruding sections 3213, and the recessed section is recessed toward the fourth edge 3112.
  • the pole tab 312 corresponds to the two adjacent protruding sections 3213 to reduce the risk of lithium precipitation at the position of the body 311 corresponding to the pole tab 312. Probability.
  • the centerline P1 of each pole tab 312 deviates from the symmetrical centerline P2 of the two protruding segments 3213 adjacent to the pole tab 312 .
  • the plurality of protruding segments 3213 are arranged at intervals along the length direction Y of the current collector 31 .
  • the plurality of protruding segments 3213 may have the same structural form.
  • Two adjacent protruding segments 3213 have a symmetrical centerline P2 .
  • the present application provides an electrode assembly 23.
  • the electrode assembly 23 includes a positive electrode piece, a separator, and a negative electrode piece.
  • the positive electrode piece, the separator, and the negative electrode piece are stacked and rolled to form the electrode assembly 23.
  • the positive electrode piece and the negative electrode piece are the electrode pieces 30 provided in the above embodiment.
  • the positive electrode piece and the negative electrode piece are the above-mentioned electrode pieces 30, which can reduce the risk of lithium precipitation in the battery cell 20 composed of the electrode assembly 23 and improve the safety of the battery cell 20. .
  • the present application provides a battery cell 20.
  • the battery cell 20 includes the electrode assembly 23 provided in the above embodiment.
  • the battery cell 20 according to the embodiment of the present application adopts the above-mentioned electrode assembly 23 and has high safety.
  • the battery cell 20 further includes a case 21, an end cover 22, a first electrode terminal 241, a second electrode terminal 242, a first current collecting member 251 and a second current collecting member.
  • the housing 21 has an opening; the end cap 22 closes the opening.
  • the first electrode terminal 241 and the second electrode terminal 242 are provided on the end cap 22 .
  • the electrode assembly 23 is accommodated in the casing 21 .
  • the extension direction of the winding axis of the electrode assembly 23 is perpendicular to the thickness direction M of the end cover 22 .
  • the positive electrode tab 312 a and the negative electrode tab 312 b of the electrode assembly 23 are respectively located on the electrode assembly 23 On both sides in the extension direction N of the winding axis, the positive electrode tab 312a is electrically connected to the first electrode terminal 241 through the first current collecting member 251, and the negative electrode tab 312b is electrically connected to the second electrode through the second current collecting member 252. Terminal 242.
  • Both the first electrode terminal 241 and the second electrode terminal 242 are conductive components for connecting the battery cells 20 export of electrical energy.
  • the direction indicated by letter M is the thickness direction of the end cap 22
  • the direction indicated by letter N is the extension direction of the winding axis of the electrode assembly 23 .
  • the extension direction N of the winding axis of the electrode assembly 23 is parallel to the width direction X of the current collector 31 .
  • the positive electrode tab 312a and the negative electrode tab 312b extend from both sides of the extension direction N of the winding axis of the electrode assembly 23 to facilitate the assembly of the electrode assembly 23 and reduce the risk of contact short circuit between the positive electrode tab 312a and the negative electrode tab 312b.
  • Both the first current collecting member 251 and the second current collecting member 252 are conductive parts with good conductive properties.
  • the material of the first current collecting member 251 and the second current collecting member 252 can be metal, such as aluminum, nickel or Its alloys etc.
  • the present application provides a battery 100 including the battery cell 20 as described in the above embodiments.
  • the present application provides an electrical device, including the battery 100 as described in the above embodiments.
  • the battery 100 is used to provide electrical energy for the electrical device.
  • the powered device can be any of the above-mentioned devices or systems that use batteries.
  • the present application provides a rectangular battery cell, which includes a casing 21, an end cover 22, an electrode assembly 23, a first electrode terminal 241, and a third Two electrode terminals 242, a first current collecting member 251 and a second current collecting member 252.
  • the housing 21 has an opening, and the end cover 22 closes the opening to define a sealed space with the housing 21 .
  • the first electrode terminal 241 and the second electrode terminal 242 are provided on the end cap 22 .
  • the electrode assembly 23 is accommodated in the housing 21 .
  • the electrode assembly 23 includes a positive electrode piece, a separator, and a negative electrode piece. The positive electrode piece, the separator, and the negative electrode piece are stacked and rolled to form the electrode assembly 23.
  • the positive electrode piece and the negative electrode piece are the electrode pieces 30 provided in the above embodiment.
  • the extension direction N of the winding axis of the electrode assembly 23 is perpendicular to the thickness direction M of the end cap 22 .
  • the positive tab 312 a and the negative tab 312 b of the electrode assembly 23 are respectively located on both sides of the electrode assembly 23 in the extension direction N of the winding axis.
  • the positive electrode tab 312a is electrically connected to the first electrode terminal 241 through the first current collecting member 251
  • the negative electrode tab 312b is electrically connected to the second electrode terminal 242 through the second current collecting member 252.
  • the pole piece 30 includes a current collector 31 and an active material layer 32 .
  • the current collector 31 includes a body 311 and a plurality of tabs 312 .
  • the body 311 includes third edges that are oppositely arranged along the thickness direction Z of the current collector 31 . 3111 and the fourth edge 3112, the tab 312 extends from the third edge 3111, and the active material layer 32 is coated on the two opposite sides of the body 311 in the thickness direction.
  • the third edge 3111 extends linearly along the length direction Y of the current collector 31
  • the fourth edge 3112 extends in an undulating manner along the length direction Y of the current collector 31 .
  • the active material layer 32 includes a first edge 321 and a second edge 322 opposite along the width direction , the second edge 322 is close to the fourth edge 3112, and the second edge 322 coincides with the fourth edge 3112.
  • the second edge 322 is symmetrically arranged with the first edge 321 .
  • the first edge 321 of the active material layer 32 of the positive electrode piece corresponds to the second edge 322 of the active material layer 32 of the negative electrode piece
  • the second edge 322 of the active material layer 32 of the positive electrode piece corresponds to the second edge 322 of the active material layer 32 of the negative electrode piece. corresponds to the first edge 321 of the active material layer 32 of the sheet.
  • the edge of the winding axis of the electrode assembly 23 in the extension direction N has less active material layer 32 , which reduces the power of the rectangular battery cells.
  • the risk of lithium precipitation makes the square battery cells highly safe.

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Aviation & Aerospace Engineering (AREA)
  • Battery Electrode And Active Subsutance (AREA)
  • Cell Electrode Carriers And Collectors (AREA)

Abstract

La présente invention appartient au domaine technique des batteries, et concerne une feuille d'électrode, un ensemble d'électrodes, un élément de batterie, une batterie et un dispositif électrique. La feuille d'électrode comprend : un collecteur de courant ; et une couche de matériau actif qui est appliquée sur la surface du collecteur de courant, la couche de matériau actif comprenant un premier bord et un second bord, qui sont opposés l'un à l'autre dans une direction de largeur du collecteur de courant, le premier bord s'étendant de manière ondulée dans une direction de longueur du collecteur de courant. Un élément de batterie, qui est composé de la feuille d'électrode, présente un niveau de sécurité relativement élevé.
PCT/CN2023/077463 2022-06-20 2023-02-21 Feuille d'électrode, ensemble d'électrodes, élément de batterie, batterie et dispositif électrique WO2023246134A1 (fr)

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CN202221547191.X 2022-06-20

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CN117637990A (zh) * 2024-01-26 2024-03-01 宁德新能源科技有限公司 极片、电极组件及电池
CN117638254A (zh) * 2024-01-26 2024-03-01 宁德新能源科技有限公司 一种电极组件及电池

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CN217788451U (zh) * 2022-06-20 2022-11-11 宁德时代新能源科技股份有限公司 极片、电极组件、电池单体、电池及用电设备
CN218867151U (zh) * 2022-11-14 2023-04-14 宁德时代新能源科技股份有限公司 一种电极构件、电池单体、电池及用电装置

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CN114641885A (zh) * 2021-06-25 2022-06-17 宁德新能源科技有限公司 一种卷绕型锂离子电池及电子装置
CN217788451U (zh) * 2022-06-20 2022-11-11 宁德时代新能源科技股份有限公司 极片、电极组件、电池单体、电池及用电设备

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JP2012009376A (ja) * 2010-06-28 2012-01-12 Nec Energy Devices Ltd 集電体電極板の製造方法
JP2018063881A (ja) * 2016-10-13 2018-04-19 株式会社東芝 二次電池、二次電池の製造方法、電極
CN114641885A (zh) * 2021-06-25 2022-06-17 宁德新能源科技有限公司 一种卷绕型锂离子电池及电子装置
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CN117637990A (zh) * 2024-01-26 2024-03-01 宁德新能源科技有限公司 极片、电极组件及电池
CN117638254A (zh) * 2024-01-26 2024-03-01 宁德新能源科技有限公司 一种电极组件及电池
CN117638254B (zh) * 2024-01-26 2024-04-26 宁德新能源科技有限公司 一种电极组件及电池
CN117637990B (zh) * 2024-01-26 2024-04-26 宁德新能源科技有限公司 极片、电极组件及电池

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